Apera PC60

[mmcr]

To other owners of the Apera PC60 meter...

I purchased mine about 6 months ago, as well as the Apera 3 point calibration kit.

I've followed the manual, and stored the probe in the provided solution when not in use. I've also used the provided (and then my purchased for 3 point) calibration solutions.

I've only used the probe 10 times or less, however the pH readings seem way out compared with a Taylor's phenol red drops test, as well when I take a sample to the local pool shop. The Apera tends to show a much higher pH (eg 9.8) when the actual pH is around 8 according to the other two methods...

If I calibrate the meter, the readings then correlate, however do I really need to calibrate the meter every single time before use ?? It seems to remain calibrated for at best two uses before requiring re-calibration, even though I'm storing it correctly and following all the other instructions (using distilled water to rinse etc)...

How long does calibration normally last for everyone else ?

 

[Ahultin]

I've had mine 1yr and calibrated 2x. It is still within tolerance to the phenol red Taylor test

 

[JoyfulNoise]

Are you sure you are storing the probe correctly and that the bulb is completely submerged in the 3M KCl storage solution?

I just used mine and calibrated it maybe 2 months ago. It was dead-on accurate. I use the PH60 but that’s just the combo one with the pH and salinity probe.

Are you following the instructions for the full 3-point calibration procedure?

Also, are you waiting for smiley face icon icon to appear on the screen telling you that the reading has stabilized?

 

[mmcr]

Are you sure you are storing the probe correctly and that the bulb is completely submerged in the 3M KCl storage solution?

Yep, it's submerged to the line on the cap, and yes I do wait for the smiley.

Mine sounds like the same model as yours (pH/EC/TDS/Sal/Temp)

Maybe I need to send it back for a check...

 

[JoyfulNoise]

Yep, it's submerged to the line on the cap, and yes I do wait for the smiley.

Mine sounds like the same model as yours (pH/EC/TDS/Sal/Temp)

Maybe I need to send it back for a check...

Maybe call their tech support line and tell them what you are seeing. The probe tips are replaceable and so maybe they’ll just send you a new tip.

 

[mmcr]

Ok well both the retailer and Apera tech support implied this was normal. Here’s what Apera said:

“For High-Accuracy measurements (≤ ±0.02pH), the meter should be calibrated before test every time; For general-accuracy Measurements (≥±0.1pH), once calibrated, the meter can be used for about a week or longer”

So looks like I need to calibrate every time if I’m not using it weekly.

What a hassle - I definitely wouldn’t have spent the $$$ on this if I’d understood this beforehand…

 

[JoyfulNoise]

Ok well both the retailer and Apera tech support implied this was normal. Here’s what Apera said:

“For High-Accuracy measurements (≤ ±0.02pH), the meter should be calibrated before test every time; For general-accuracy Measurements (≥±0.1pH), once calibrated, the meter can be used for about a week or longer”

So looks like I need to calibrate every time if I’m not using it weekly.

What a hassle - I definitely wouldn’t have spent the $$$ on this if I’d understood this beforehand…

But why do you need +\-0.02 tolerance? It’s unnecessary in pool water. You can calibrate it once and then it will easily go for a month or more in my experience and the tolerance and accuracy as compared to phenol red is spot on.

 

[an1vrsy]

I use the PH60 but that’s just the combo one with the pH and salinity probe.

Salinity? Do I have to change out the probe to get salinity? I have only tested pH with this meter. Or do I have to read the manual and change some settings?

 

[Ahultin]

For general-accuracy Measurements (≥±0.1pH), once calibrated, the meter can be used for about a week or longer”

I have not found this to be the case BUT, I use the 1 function ph60 vs your multi function pc60, I wonder if that is the difference or they are just being overly cautious. There is no way I would use it if I had to calibrate weekly. Roughly monthly I do use the phenol red test and compare and it's been perfectly within "pool tolerance" for me

 

[mmcr]

I wonder if it's my calibration solutions. I left some in the purpose made Apera holder (with the lids on).

The pH 4 calibration was way off (can't remember the number, but the probe locked on something that was more than 0.4 away from 4.0), so I tipped that out and poured in some fresh 4.0, and it got much closer.

However, despite a fresh 'pour' of the 10.01 solution, the probe locks in at ~9.59

But if it's reading my water higher than what I think it is (so reading at 8.5-9, when I think it's 8 at best), having the probe calibrated at 9.6 for the 10.01 mark also doesn't quite make sense to me (if anything it should read lower ?) ?!

I wonder if I should buy some new calibration solutions. How long are they supposed to last if stored with lids on in a sensible place ?

 

[JamesW]

Salinity? Do I have to change out the probe to get salinity? I have only tested pH with this meter. Or do I have to read the manual and change some settings?

https://s3.amazonaws.com/zcom-media/sites/a0i0L00000VJHGsQAP/media/mediamanager/PC60_Tester_Manual_v8.1.pdf

​

PC60 Premium Multiparameter (pH/EC/TDS/Salinity/Temp.) Pocket Tester Kit.​

PH60 Premium Pocket pH Tester Kit.​

PC60 Premium Multiparameter (pH/EC/TDS/Salinity/Temperature) Pocket Tester/Meter Kit-Apera Instruments

The Apera Instruments PC60 Multi-parameter Tester/Meter simply tests pH/EC/TDS/Salinity/Temperature for regular aqueous solutions such as hydroponics, aquaculture, pools& spas, tap/drinking water, water treatment, cooling towers, etc.

aperainst.com

60 Series Portable Premium Pocket pH/EC/Salinity/TDS/ORP Meters and Testers

Apera Instruments 60 series portable premium pocket pH/EC/Salinity/TDS/ORP Meters and Testers are designed for regular multi-parameter measurements in soil, hydroponics, brewing, water testing, food and dairy products, and pools and spas.

aperainst.com

 

[mmcr]

I wonder if it's my calibration solutions. I left some in the purpose made Apera holder (with the lids on).

The pH 4 calibration was way off (can't remember the number, but the probe locked on something that was more than 0.4 away from 4.0), so I tipped that out and poured in some fresh 4.0, and it got much closer.

However, despite a fresh 'pour' of the 10.01 solution, the probe locks in at ~9.59

But if it's reading my water higher than what I think it is (so reading at 8.5-9, when I think it's 8 at best), having the probe calibrated at 9.6 for the 10.01 mark also doesn't quite make sense to me (if anything it should read lower ?) ?!

I wonder if I should buy some new calibration solutions. How long are they supposed to last if stored with lids on in a sensible place ?

Ok so to close the loop on this…

After explaining to the retailer that the unit took ages (several minutes) to fix on a reading (smiley face), they sent me a new unit.

I’ve been using it for a couple of months now after the initial calibration, and it’s been fine. It definitely fixes on a reading during calibration and testing much faster.

So it seems like it was a faulty unit after all.

Thanks all for the advice

 

[SoDel]

Glad you figured it out. I had an issue with getting consistent readings until I was much more careful with keeping the calibration solutions “pristine.” It may seem obvious but it wasn’t to me at the time so I’ll get into it. When calibrating, I rinse the KCl off the probe with tap water and then rinse the tap water off the probe with distilled water, dry the probe, then into the first calibration solution. Same routine prior to each calibration solution, rinse with running tap water then in distilled water, wipe dry and onward. I suspect I had been contaminating my distilled water rinse with calibration solutions or something was going on where I was not calibrating properly and had inexplicable measurements. Much more consistent now. Maybe there’s an even better way (question for our resident experts)?

 

[duraleigh]

What a hassle - I definitely wouldn’t have spent the $$$ on this if I’d understood this beforehand…

I would say the same for ALL digital pH meters. Too often, some HAVE TO have the latest and greatest technology and so the great unwashed masses out there chose digital.......Bad Choice! The brand doesn't alter what I am saying

The inexpensive drops based Phenol Red test is the easiest fastest, most consistent AND cheapest test on the market. Perfectly accurate, as well

Don't use color-blind as an excuse, either. There are too many work arounds